Fan Blade

ABSTRACT

A heating, ventilation, and/or air conditioning (HVAC) system includes an outdoor unit having an outdoor fan configured to generate an airflow. The outdoor fan includes a fan blade assembly having a plurality of fan blades. Each fan blades is formed from a constant and/or uniform thickness material and includes an upwardly curved leading edge that causes a lower surface of the fan blade to contact the air first as the fan blade assembly is rotated and causes air attachment to the lower surface such that an eddy of air is trapped, recirculated, and/or generally passed more slowly through a recirculation zone, defined generally as the angularly trailing space behind the upwardly curved leading edge and between the upwardly curved leading edge and the remainder of an upper surface.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. 119(e) to U.S. Provisional Patent Application No. 62/062,572 filed on Oct. 10, 2014 by Stephen Stewart Hancock and entitled “Fan Blade,” the disclosure of which is hereby incorporated by reference in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO A MICROFICHE APPENDIX

Not applicable.

BACKGROUND

Heating, ventilation, and/or air conditioning (HVAC) systems may generally be used in residential and/or commercial structures to provide heating and/or cooling to climate-controlled areas within these structures. Some HVAC systems may be heat pump systems that include both an indoor unit and an outdoor unit and that are selectively operable between a cooling mode of operation and a heating mode of operation. Most HVAC systems comprise at least one fan having a fan blade assembly configured to generate an airflow and pass the airflow into contact with at least one heat exchanger to exchange heat between the airflow and a refrigerant carried within internal passages of the heat exchanger. However, some fan blade assemblies may be inefficient for its intended purpose.

SUMMARY

In some embodiments of the disclosure, a heating, ventilation, and/or air conditioning (HVAC) system is disclosed as comprising: a fan blade assembly, the fan blade assembly comprising at least one fan blade comprising an upwardly curved leading portion.

In other embodiments of the disclosure, a method of manufacturing a fan blade is disclosed as comprising: providing a sheet of substantially constant thickness material; and stamping the sheet into a form comprising at least one of an upwardly curved leading portion.

In yet other embodiments of the disclosure, a fan blade is disclosed as comprising: a uniform thickness material; and a upwardly curved leading portion.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and the advantages thereof, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description:

FIG. 1 is a schematic diagram of an HVAC system according to an embodiment of the disclosure;

FIG. 2 is an orthogonal top view of a fan blade assembly of an outdoor fan of the HVAC system of FIG. 1 according to an embodiment of the disclosure;

FIG. 3 is an orthogonal bottom view of the fan blade assembly of FIG. 2 according to an embodiment of the disclosure;

FIG. 4 is an orthogonal side view of the fan blade assembly of FIG. 2 according to an embodiment of the disclosure;

FIG. 5A is an orthogonal side view of a fan blade of the fan blade assembly of FIG. 2 according to an embodiment of the disclosure;

FIG. 5B is an orthogonal right projection view of the fan blade of FIG. 5A according to an embodiment of the disclosure;

FIG. 5C is an orthogonal left projection view of the fan blade of FIGS. 5A-5B according to an embodiment of the disclosure;

FIG. 5D is an orthogonal top projection view of the fan blade of FIGS. 5A-5C according to an embodiment of the disclosure;

FIG. 5E is an orthogonal bottom projection view of the fan blade of FIGS. 5A-5D according to an embodiment of the disclosure;

FIG. 6A is an orthogonal side view of the fan blade of FIGS. 5A-5E according to an embodiment of the disclosure; and

FIG. 6B is an orthogonal left projection view of the fan blade of FIG. 6A according to an embodiment of the disclosure.

DETAILED DESCRIPTION

Referring now to FIG. 1, a schematic diagram of an HVAC system 100 according to an embodiment of this disclosure is shown. HVAC system 100 comprises an indoor unit 102, an outdoor unit 104, and a system controller 106. In some embodiments, the system controller 106 may operate to control operation of the indoor unit 102 and/or the outdoor unit 104. As shown, the HVAC system 100 is a so-called heat pump system that may be selectively operated to implement one or more substantially closed thermodynamic refrigeration cycles to provide a cooling functionality and/or a heating functionality. In alternative embodiments, the HVAC system 100 may comprise a type of air-conditioning system that is not a heat pump system.

Indoor unit 102 comprises an indoor heat exchanger 108, an indoor fan 110, and an indoor metering device 112. Indoor heat exchanger 108 is a plate fin heat exchanger configured to allow heat exchange between refrigerant carried within internal tubing of the indoor heat exchanger 108 and fluids that contact the indoor heat exchanger 108 but that are kept segregated from the refrigerant. In other embodiments, indoor heat exchanger 108 may comprise a spine fin heat exchanger, a microchannel heat exchanger, or any other suitable type of heat exchanger.

The indoor fan 110 is a centrifugal blower comprising a blower housing, a blower impeller at least partially disposed within the blower housing, and a blower motor configured to selectively rotate the blower impeller. In other embodiments, the indoor fan 110 may comprise a mixed-flow fan and/or any other suitable type of fan. The indoor fan 110 is configured as a modulating and/or variable speed fan capable of being operated at many speeds over one or more ranges of speeds. In other embodiments, the indoor fan 110 may be configured as a multiple speed fan capable of being operated at a plurality of operating speeds by selectively electrically powering different ones of multiple electromagnetic windings of a motor of the indoor fan 110. In yet other embodiments, the indoor fan 110 may be a single speed fan.

The indoor metering device 112 is an electronically controlled motor driven electronic expansion valve (EEV). In alternative embodiments, the indoor metering device 112 may comprise a thermostatic expansion valve, a capillary tube assembly, and/or any other suitable metering device. The indoor metering device 112 may comprise and/or be associated with a refrigerant check valve and/or refrigerant bypass for use when a direction of refrigerant flow through the indoor metering device 112 is such that the indoor metering device 112 is not intended to meter or otherwise substantially restrict flow of the refrigerant through the indoor metering device 112.

Outdoor unit 104 comprises an outdoor heat exchanger 114, a compressor 116, an outdoor fan 118, an outdoor metering device 120, and a reversing valve 122. Outdoor heat exchanger 114 is a spine fin heat exchanger configured to allow heat exchange between refrigerant carried within internal passages of the outdoor heat exchanger 114 and fluids that contact the outdoor heat exchanger 114 but that are kept segregated from the refrigerant. In other embodiments, outdoor heat exchanger 114 may comprise a plate fin heat exchanger, a microchannel heat exchanger, or any other suitable type of heat exchanger.

The compressor 116 is a multiple speed scroll type compressor configured to selectively pump refrigerant at a plurality of mass flow rates. In alternative embodiments, the compressor 116 may comprise a modulating compressor capable of operation over one or more speed ranges, the compressor 116 may comprise a reciprocating type compressor, the compressor 116 may be a single speed compressor, and/or the compressor 116 may comprise any other suitable refrigerant compressor and/or refrigerant pump.

The outdoor fan 118 is an axial fan comprising a fan blade assembly 200 and fan motor configured to selectively rotate the fan blade assembly 200. In other embodiments, the outdoor fan 118 may comprise a mixed-flow fan, a centrifugal blower, and/or any other suitable type of fan and/or blower. The outdoor fan 118 is configured as a modulating and/or variable speed fan capable of being operated at many speeds over one or more ranges of speeds. In other embodiments, the outdoor fan 118 may be configured as a multiple speed fan capable of being operated at a plurality of operating speeds by selectively electrically powering different ones of multiple electromagnetic windings of a motor of the outdoor fan 118. In yet other embodiments, the outdoor fan 118 may be a single speed fan.

The outdoor metering device 120 is a thermostatic expansion valve. In alternative embodiments, the outdoor metering device 120 may comprise an electronically controlled motor driven EEV, a capillary tube assembly, and/or any other suitable metering device. The outdoor metering device 120 may comprise and/or be associated with a refrigerant check valve and/or refrigerant bypass for use when a direction of refrigerant flow through the outdoor metering device 120 is such that the outdoor metering device 120 is not intended to meter or otherwise substantially restrict flow of the refrigerant through the outdoor metering device 120.

The reversing valve 122 is a so-called four-way reversing valve. The reversing valve 122 may be selectively controlled to alter a flow path of refrigerant in the HVAC system 100 as described in greater detail below. The reversing valve 122 may comprise an electrical solenoid or other device configured to selectively move a component of the reversing valve 122 between operational positions.

The system controller 106 may comprise a touchscreen interface for displaying information and for receiving user inputs. The system controller 106 may display information related to the operation of the HVAC system 100 and may receive user inputs related to operation of the HVAC system 100. However, the system controller 106 may further be operable to display information and receive user inputs tangentially and/or unrelated to operation of the HVAC system 100. In some embodiments, the system controller 106 may comprise a temperature sensor and may further be configured to control heating and/or cooling of zones associated with the HVAC system 100. In some embodiments, the system controller 106 may be configured as a thermostat for controlling supply of conditioned air to zones associated with the HVAC system.

In some embodiments, the system controller 106 may selectively communicate with an indoor controller 124 of the indoor unit 102, with an outdoor controller 126 of the outdoor unit 104, and/or with other components of the HVAC system 100. In some embodiments, the system controller 106 may be configured for selective bidirectional communication over a communication bus 128. In some embodiments, portions of the communication bus 128 may comprise a three-wire connection suitable for communicating messages between the system controller 106 and one or more of the HVAC system 100 components configured for interfacing with the communication bus 128. Still further, the system controller 106 may be configured to selectively communicate with HVAC system 100 components and/or other devices 130 via a communication network 132. Still further, the system controller 106 may be configured to selectively communicate with other systems via the communication network 132. In some embodiments, the system controller 106 may communicate with weather data providers 133, customized data providers 131 such as home automation service providers, and/or other data providers 129.

The indoor controller 124 may be carried by the indoor unit 102 and may be configured to receive information inputs, transmit information outputs, and otherwise communicate with the system controller 106, the outdoor controller 126, and/or any other device via the communication bus 128 and/or any other suitable medium of communication. In some embodiments, the indoor controller 124 may be configured to communicate with an indoor personality module 134, receive information related to a speed of the indoor fan 110, transmit a control output to an electric heat relay, transmit information regarding an indoor fan 110 volumetric flow-rate, communicate with and/or otherwise affect control over an air cleaner 136, and communicate with an indoor EEV controller 138. In some embodiments, the indoor controller 124 may be configured to communicate with an indoor fan controller 142 and/or otherwise affect control over operation of the indoor fan 110. In some embodiments, the indoor personality module 134, or any other suitable information storage device, may comprise information related to the identification and/or operation of the indoor unit 102 and/or a position of the outdoor metering device 120.

In some embodiments, the indoor EEV controller 138 may be configured to receive information regarding temperatures and pressures of the refrigerant in the indoor unit 102. More specifically, the indoor EEV controller 138 may be configured to receive information regarding temperatures and pressures of refrigerant entering, exiting, and/or within the indoor heat exchanger 108. Further, the indoor EEV controller 138 may be configured to communicate with the indoor metering device 112 and/or otherwise affect control over the indoor metering device 112.

The outdoor controller 126 may be carried by the outdoor unit 104 and may be configured to receive information inputs, transmit information outputs, and otherwise communicate with the system controller 106, the indoor controller 124, and/or any other device via the communication bus 128 and/or any other suitable medium of communication. In some embodiments, the outdoor controller 126 may be configured to communicate with an outdoor personality module 140 that may comprise information related to the identification and/or operation of the outdoor unit 104. In some embodiments, the outdoor controller 126 may be configured to receive information related to an ambient temperature associated with the outdoor unit 104, information related to a temperature of the outdoor heat exchanger 114, and/or information related to refrigerant temperatures and/or pressures of refrigerant entering, exiting, and/or within the outdoor heat exchanger 114 and/or the compressor 116. In some embodiments, the outdoor controller 126 may be configured to transmit information related to monitoring, communicating with, and/or otherwise affecting control over the outdoor fan 118, a compressor sump heater, a solenoid of the reversing valve 122, a relay associated with adjusting and/or monitoring a refrigerant charge of the HVAC system 100, a position of the indoor metering device 112, and/or a position of the outdoor metering device 120. The outdoor controller 126 may further be configured to communicate with a compressor drive controller 144 that is configured to electrically power and/or control the compressor 116.

The HVAC system 100 is shown configured for operating in a so-called cooling mode in which heat is absorbed by refrigerant at the indoor heat exchanger 108 and heat is rejected from the refrigerant at the outdoor heat exchanger 114. In some embodiments, the compressor 116 may be operated to compress refrigerant and pump the relatively high temperature and high pressure compressed refrigerant from the compressor 116 to the outdoor heat exchanger 114 through the reversing valve 122 and to the outdoor heat exchanger 114. As the refrigerant is passed through the outdoor heat exchanger 114, the outdoor fan 118 may be operated to move air into contact with the outdoor heat exchanger 114, thereby transferring heat from the refrigerant to the air surrounding the outdoor heat exchanger 114. The refrigerant may primarily comprise liquid phase refrigerant and the refrigerant may be pumped from the outdoor heat exchanger 114 to the indoor metering device 112 through and/or around the outdoor metering device 120 which does not substantially impede flow of the refrigerant in the cooling mode. The indoor metering device 112 may meter passage of the refrigerant through the indoor metering device 112 so that the refrigerant downstream of the indoor metering device 112 is at a lower pressure than the refrigerant upstream of the indoor metering device 112. The pressure differential across the indoor metering device 112 allows the refrigerant downstream of the indoor metering device 112 to expand and/or at least partially convert to gaseous phase. The gaseous phase refrigerant may enter the indoor heat exchanger 108. As the refrigerant is passed through the indoor heat exchanger 108, the indoor fan 110 may be operated to move air into contact with the indoor heat exchanger 108, thereby transferring heat to the refrigerant from the air surrounding the indoor heat exchanger 108. The refrigerant may thereafter reenter the compressor 116 after passing through the reversing valve 122.

To operate the HVAC system 100 in the so-called heating mode, the reversing valve 122 may be controlled to alter the flow path of the refrigerant, the indoor metering device 112 may be disabled and/or bypassed, and the outdoor metering device 120 may be enabled. In the heating mode, refrigerant may flow from the compressor 116 to the indoor heat exchanger 108 through the reversing valve 122, the refrigerant may be substantially unaffected by the indoor metering device 112, the refrigerant may experience a pressure differential across the outdoor metering device 120, the refrigerant may pass through the outdoor heat exchanger 114, and the refrigerant may reenter the compressor 116 after passing through the reversing valve 122. Most generally, operation of the HVAC system 100 in the heating mode reverses the roles of the indoor heat exchanger 108 and the outdoor heat exchanger 114 as compared to their operation in the cooling mode.

Referring now to FIGS. 2-6B, multiple orthogonal views of the fan blade assembly 200 of the outdoor fan 118 of HVAC system 100 of FIG. 1 are shown according to an embodiment of the disclosure. The fan blade assembly 200 generally comprises a plurality of fan blades 204 and a central axis 202 about which the fan blade assembly 200 may be rotated. Although not shown, it will be appreciated that a fan assembly hub may be further provided and that the hub may generally be located coaxially with the central axis 202. The fan assembly hub may generally comprise a central tubular member joined to each fan blade 204 either integrally or through the use of fasteners, such as bolts, rivets, and/or any other suitable connection. Additionally, in some embodiments, a shaft of a motor of the outdoor fan 118 may extend substantially coaxially with the central axis 202 and received within the hub that may be joined to the plurality of fan blades 204. In this embodiment, each fan blade 204 is formed by stamping a substantially constant and/or uniform thickness metal sheet into the curved embodiment shown. However, in alternative embodiments, the fan blades 204 may comprise multiple layers of materials that are amenable to being stamped, rolled, and/or otherwise deformed from a substantially flat bulk material into the above described shape, such that the fan blades comprise a substantially constant and/or uniform thickness.

Each fan blade 204 generally comprises an upper surface 206, a lower surface 208, a leading edge 210, a trailing edge 212, an inside edge 214, and an outside edge 216. In operation, the fan blade assembly 200 may general be rotated about the central axis 202 in a counter-clockwise direction 218 as viewed from above so that the blades 204 generally move air axially from a location nearer the leading edge 210 to a location nearer the trailing edge 214.

In this embodiment, the leading edge 210 is generally associated with an upward curvature 220 of the fan blade 204 that represents a leading edge 210 hook. The upward curvature 220 generally causes the lower surface 208 to be forced into contact with the air first as the fan blade assembly 200 is rotated. In some embodiments, the upward curvature 220 causes air attachment to the lower surface 208, such that an eddy of air is trapped, recirculated, and/or generally passed more slowly through a recirculation zone 222, defined generally as the angularly trailing space behind the upward curvature 220 and between the upward curvature 220 and the remainder of the upper surface 206 as compared to air that does not pass through the recirculation zone 222. In some cases, the upward curvature 220 may provide performance increases and/or emulate the performance of a three dimensional airfoil blade even though the fan blade 204 comprises a single thickness material such as sheet metal and/or comprises a substantially constant and/or uniform combined thickness of structural materials throughout the fan blade 204. In some embodiments, the upward curvature 220 of the fan blade 204 comprises a maximum curvature near the leading edge 210 and diminishes continuously until reaching a minimum curvature near the trailing edge 212 of the fan blade 204. Accordingly, the maximum curvature near the leading edge 210 may be associated with a smallest radius curvature, while the minimum curvature near the trailing edge 212 may be associated with a largest radius curvature. The upward curvature 220 causes air to attach to the low pressure side 208 of the fan blade 204 providing efficiency, stall, noise, and/or lift/drag ratio improvements as compared to single thickness fan blades lacking such an upward curvature 220. In some embodiments, the fan blade 204 may be based on a transformation of the Gottingen 417a profile modified for the rotational condition of the fan blade 204. Additionally, while the fan assembly 200 is described herein as being a component of the outdoor fan 118 of outdoor unit 104 of HVAC system 100, it will be appreciated that fan assembly 200 may alternatively be used in the indoor fan 110 of the indoor unit 102 of HVAC system 100 and/or any other fan and/or blower.

A method of manufacturing a fan blade 204 may comprise first providing a sheet of material. In some embodiments, the sheet of material may comprise metal, plastic, and/or any other material having a substantially constant and/or uniform thickness. However, in some embodiments, the sheet of material may comprise a laminate and/or other material comprising multiple layers of material having a substantially constant and/or uniform thickness. Next, the method may comprise stamping, forming, cutting, and/or otherwise bending the sheet of material into one or more of the above-described fan blade shapes, such as the shape of fan blade 204. In some embodiments, however, the fan blade 204 may be formed by injection or compression molding and/or milling processes.

At least one embodiment is disclosed and variations, combinations, and/or modifications of the embodiment(s) and/or features of the embodiment(s) made by a person having ordinary skill in the art are within the scope of the disclosure. Alternative embodiments that result from combining, integrating, and/or omitting features of the embodiment(s) are also within the scope of the disclosure. Where numerical ranges or limitations are expressly stated, such express ranges or limitations should be understood to include iterative ranges or limitations of like magnitude falling within the expressly stated ranges or limitations (e.g., from about 1 to about 10 includes, 2, 3, 4, etc.; greater than 0.10 includes 0.11, 0.12, 0.13, etc.). For example, whenever a numerical range with a lower limit, R₁, and an upper limit, R_(u), is disclosed, any number falling within the range is specifically disclosed. In particular, the following numbers within the range are specifically disclosed: R=R₁+k*(R_(u)−R₁), wherein k is a variable ranging from 1 percent to 100 percent with a 1 percent increment, i.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent, . . . 50 percent, 51 percent, 52 percent, . . . , 95 percent, 96 percent, 97 percent, 98 percent, 99 percent, or 100 percent. Moreover, any numerical range defined by two R numbers as defined in the above is also specifically disclosed. Use of the term “optionally” with respect to any element of a claim means that the element is required, or alternatively, the element is not required, both alternatives being within the scope of the claim. Use of broader terms such as comprises, includes, and having should be understood to provide support for narrower terms such as consisting of, consisting essentially of, and comprised substantially of. Accordingly, the scope of protection is not limited by the description set out above but is defined by the claims that follow, that scope including all equivalents of the subject matter of the claims. Each and every claim is incorporated as further disclosure into the specification and the claims are embodiment(s) of the present invention. 

What is claimed is:
 1. A heating, ventilation, and/or air conditioning (HVAC) system, comprising: a fan blade assembly, the fan blade assembly comprising: at least one fan blade comprising an upwardly curved leading portion.
 2. The HVAC system of claim 1, wherein the upwardly curved leading portion is configured to serve as a boundary for an air recirculation zone.
 3. The HVAC system of claim 1, wherein the upwardly curved leading portion is configured to cause a lower surface of the at least one fan blade to serve as a leading portion of the at least one fan blade.
 4. The HVAC system of claim 1, wherein the upwardly curved leading portion is configured to attach flow to the low pressure side of the fan blade.
 5. The HVAC system of claim 4, wherein an upper surface of the at least one fan blade is configured to serve as a trailing boundary for the air recirculation zone.
 6. The HVAC system of claim 1, wherein the upwardly curved leading portion comprises at least one of a stamped form and a substantially single thickness material.
 7. The HVAC system of claim 1, wherein the upwardly curved leading portion comprises a hook configured to serve as a leading boundary for an air recirculation zone.
 8. The HVAC system of claim 1, wherein the fan blade assembly comprises two or more fan blades.
 9. The HVAC system of claim 1, wherein the at least one fan blade comprises stamped sheet aluminum.
 10. The HVAC system of claim 1, wherein the at least one fan blade comprises stamped sheet steel.
 11. The HVAC system of claim 1, wherein the at least one fan blade comprises plastic.
 12. The HVAC system of claim 1, wherein the at least one fan blade is based on a transformation of the Gottingen 417a profile.
 13. A method of manufacturing a fan blade, comprising: providing a sheet of substantially constant thickness material; and stamping the sheet into a form comprising at least one of an upwardly curved leading portion.
 14. The method of claim 13, wherein the sheet comprises metal.
 15. The method of claim 13, wherein the form is based on a transformation of the Gottingen 417a profile.
 16. The method of claim 13, wherein the upwardly curved leading portion is configured to serve as a leading boundary for an air recirculation zone.
 17. A fan blade, comprising: a uniform thickness material; and a upwardly curved leading portion.
 18. The fan blade of claim 17, wherein the single thickness material comprises stamped sheet metal.
 19. The fan blade of claim 17, wherein the upwardly curved leading portion is configured to serve as a boundary for an air recirculation zone.
 20. The fan blade of claim 17, wherein the upwardly curved leading portion is configured to cause a lower surface of the fan blade to serve as a leading portion of the fan blade. 